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How Can I Achieve Compatibility Between ExtendPathMode and Kubernetes client-go?

Application Scenario

The Kubernetes pod structure does not contain ExtendPathMode. Therefore, when a user calls the API for creating a pod or deployment by using client-go, the created pod does not contain ExtendPathMode. CCE provides a solution to ensure compatibility with the Kubernetes client-go.

Solution

Notice
  • When creating a pod, you need to add kubernetes.io/extend-path-mode to annotation of the pod.
  • When creating a Deployment, you need to add kubernetes.io/extend-path-mode to kubernetes.io/extend-path-mode in the template.

The following is an example YAML of creating a pod. After the kubernetes.io/extend-path-mode keyword is added to annotation, the containername, name, and mountpath fields are matched, and the corresponding extendpathmode is added to volumeMount.

apiVersion: v1
kind: Pod
metadata:
name: test-8b59d5884-96vdz
generateName: test-8b59d5884-
namespace: default
selfLink: /api/v1/namespaces/default/pods/test-8b59d5884-96vdz
labels:
app: test
pod-template-hash: 8b59d5884
annotations:
kubernetes.io/extend-path-mode: '[{"containername":"container-0","name":"vol-156738843032165499","mountpath":"/tmp","extendpathmode":"PodUID"}]'
metrics.alpha.kubernetes.io/custom-endpoints: '[{"api":"","path":"","port":"","names":""}]'
ownerReferences:
- apiVersion: apps/v1
kind: ReplicaSet
name: test-8b59d5884
uid: 2633020b-cd23-11e9-8f83-fa163e592534
controller: true
blockOwnerDeletion: true
spec:
volumes:
- name: vol-156738843032165499
hostPath:
path: /tmp
type: ''
- name: default-token-4s959
secret:
secretName: default-token-4s959
defaultMode: 420
containers:
- name: container-0
image: 'nginx:latest'
env:
- name: PAAS_APP_NAME
value: test
- name: PAAS_NAMESPACE
value: default
- name: PAAS_PROJECT_ID
value: b6315dd3d0ff4be5b31a963256794989
resources:
limits:
cpu: 250m
memory: 512Mi
requests:
cpu: 250m
memory: 512Mi
volumeMounts:
- name: vol-156738843032165499
mountPath: /tmp
extendPathMode: PodUID
- name: default-token-4s959
readOnly: true
mountPath: /var/run/secrets/kubernetes.io/serviceaccount
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
imagePullPolicy: Always
restartPolicy: Always
terminationGracePeriodSeconds: 30
dnsPolicy: ClusterFirst
serviceAccountName: default
serviceAccount: default
nodeName: 192.168.0.24
securityContext: {}
imagePullSecrets:
- name: default-secret
- name: default-secret
affinity: {}
schedulerName: default-scheduler
tolerations:
- key: node.kubernetes.io/not-ready
operator: Exists
effect: NoExecute
tolerationSeconds: 300
- key: node.kubernetes.io/unreachable
operator: Exists
effect: NoExecute
tolerationSeconds: 300
priority: 0
dnsConfig:
options:
- name: timeout
value: ''
- name: ndots
value: '5'
- name: single-request-reopen
enableServiceLinks: true
Table 1 Descriptions of key parameters

Parameter

Type

Description

containername

String

Name of a container.

name

String

Name of a volume.

mountpath

String

Mount path.

extendpathmode

String

A third-level directory is added to the created volume directory/subdirectory to facilitate the obtaining of a single pod output file.

The following types are supported.

  • None: The extended path is not configured.
  • PodUID: ID of a pod.
  • PodName: Name of a pod.
  • PodUID/ContainerName: ID of a pod or name of a container.
  • PodName/ContainerName: Name of a pod or container.